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Diffstat (limited to 'kernel/locking/lockdep.c')
-rw-r--r--kernel/locking/lockdep.c92
1 files changed, 78 insertions, 14 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 50d4863974e7..4dfd2f3e09b2 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1881,6 +1881,8 @@ print_circular_lock_scenario(struct held_lock *src,
struct lock_class *source = hlock_class(src);
struct lock_class *target = hlock_class(tgt);
struct lock_class *parent = prt->class;
+ int src_read = src->read;
+ int tgt_read = tgt->read;
/*
* A direct locking problem where unsafe_class lock is taken
@@ -1908,7 +1910,10 @@ print_circular_lock_scenario(struct held_lock *src,
printk(" Possible unsafe locking scenario:\n\n");
printk(" CPU0 CPU1\n");
printk(" ---- ----\n");
- printk(" lock(");
+ if (tgt_read != 0)
+ printk(" rlock(");
+ else
+ printk(" lock(");
__print_lock_name(target);
printk(KERN_CONT ");\n");
printk(" lock(");
@@ -1917,7 +1922,12 @@ print_circular_lock_scenario(struct held_lock *src,
printk(" lock(");
__print_lock_name(target);
printk(KERN_CONT ");\n");
- printk(" lock(");
+ if (src_read != 0)
+ printk(" rlock(");
+ else if (src->sync)
+ printk(" sync(");
+ else
+ printk(" lock(");
__print_lock_name(source);
printk(KERN_CONT ");\n");
printk("\n *** DEADLOCK ***\n\n");
@@ -2253,6 +2263,9 @@ static inline bool usage_match(struct lock_list *entry, void *mask)
static inline bool usage_skip(struct lock_list *entry, void *mask)
{
+ if (entry->class->lock_type == LD_LOCK_NORMAL)
+ return false;
+
/*
* Skip local_lock() for irq inversion detection.
*
@@ -2279,14 +2292,16 @@ static inline bool usage_skip(struct lock_list *entry, void *mask)
* As a result, we will skip local_lock(), when we search for irq
* inversion bugs.
*/
- if (entry->class->lock_type == LD_LOCK_PERCPU) {
- if (DEBUG_LOCKS_WARN_ON(entry->class->wait_type_inner < LD_WAIT_CONFIG))
- return false;
+ if (entry->class->lock_type == LD_LOCK_PERCPU &&
+ DEBUG_LOCKS_WARN_ON(entry->class->wait_type_inner < LD_WAIT_CONFIG))
+ return false;
- return true;
- }
+ /*
+ * Skip WAIT_OVERRIDE for irq inversion detection -- it's not actually
+ * a lock and only used to override the wait_type.
+ */
- return false;
+ return true;
}
/*
@@ -4531,7 +4546,13 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
return 0;
}
}
- if (!hlock->hardirqs_off) {
+
+ /*
+ * For lock_sync(), don't mark the ENABLED usage, since lock_sync()
+ * creates no critical section and no extra dependency can be introduced
+ * by interrupts
+ */
+ if (!hlock->hardirqs_off && !hlock->sync) {
if (hlock->read) {
if (!mark_lock(curr, hlock,
LOCK_ENABLED_HARDIRQ_READ))
@@ -4752,7 +4773,8 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
for (; depth < curr->lockdep_depth; depth++) {
struct held_lock *prev = curr->held_locks + depth;
- u8 prev_inner = hlock_class(prev)->wait_type_inner;
+ struct lock_class *class = hlock_class(prev);
+ u8 prev_inner = class->wait_type_inner;
if (prev_inner) {
/*
@@ -4762,6 +4784,14 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
* Also due to trylocks.
*/
curr_inner = min(curr_inner, prev_inner);
+
+ /*
+ * Allow override for annotations -- this is typically
+ * only valid/needed for code that only exists when
+ * CONFIG_PREEMPT_RT=n.
+ */
+ if (unlikely(class->lock_type == LD_LOCK_WAIT_OVERRIDE))
+ curr_inner = prev_inner;
}
}
@@ -4910,7 +4940,7 @@ static int __lock_is_held(const struct lockdep_map *lock, int read);
static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check, int hardirqs_off,
struct lockdep_map *nest_lock, unsigned long ip,
- int references, int pin_count)
+ int references, int pin_count, int sync)
{
struct task_struct *curr = current;
struct lock_class *class = NULL;
@@ -4961,7 +4991,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
class_idx = class - lock_classes;
- if (depth) { /* we're holding locks */
+ if (depth && !sync) {
+ /* we're holding locks and the new held lock is not a sync */
hlock = curr->held_locks + depth - 1;
if (hlock->class_idx == class_idx && nest_lock) {
if (!references)
@@ -4995,6 +5026,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->trylock = trylock;
hlock->read = read;
hlock->check = check;
+ hlock->sync = !!sync;
hlock->hardirqs_off = !!hardirqs_off;
hlock->references = references;
#ifdef CONFIG_LOCK_STAT
@@ -5056,6 +5088,10 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (!validate_chain(curr, hlock, chain_head, chain_key))
return 0;
+ /* For lock_sync(), we are done here since no actual critical section */
+ if (hlock->sync)
+ return 1;
+
curr->curr_chain_key = chain_key;
curr->lockdep_depth++;
check_chain_key(curr);
@@ -5197,7 +5233,7 @@ static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
hlock->read, hlock->check,
hlock->hardirqs_off,
hlock->nest_lock, hlock->acquire_ip,
- hlock->references, hlock->pin_count)) {
+ hlock->references, hlock->pin_count, 0)) {
case 0:
return 1;
case 1:
@@ -5667,7 +5703,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
lockdep_recursion_inc();
__lock_acquire(lock, subclass, trylock, read, check,
- irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
+ irqs_disabled_flags(flags), nest_lock, ip, 0, 0, 0);
lockdep_recursion_finish();
raw_local_irq_restore(flags);
}
@@ -5693,6 +5729,34 @@ void lock_release(struct lockdep_map *lock, unsigned long ip)
}
EXPORT_SYMBOL_GPL(lock_release);
+/*
+ * lock_sync() - A special annotation for synchronize_{s,}rcu()-like API.
+ *
+ * No actual critical section is created by the APIs annotated with this: these
+ * APIs are used to wait for one or multiple critical sections (on other CPUs
+ * or threads), and it means that calling these APIs inside these critical
+ * sections is potential deadlock.
+ */
+void lock_sync(struct lockdep_map *lock, unsigned subclass, int read,
+ int check, struct lockdep_map *nest_lock, unsigned long ip)
+{
+ unsigned long flags;
+
+ if (unlikely(!lockdep_enabled()))
+ return;
+
+ raw_local_irq_save(flags);
+ check_flags(flags);
+
+ lockdep_recursion_inc();
+ __lock_acquire(lock, subclass, 0, read, check,
+ irqs_disabled_flags(flags), nest_lock, ip, 0, 0, 1);
+ check_chain_key(current);
+ lockdep_recursion_finish();
+ raw_local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(lock_sync);
+
noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
{
unsigned long flags;
generated by cgit (git 2.34.1) at 2025-10-28 16:04:20 +0000